Abstract: Aiming at the problem that more and more distributed generation is connected to the distribution network but the access location and capacity are lack of reasonable technical analysis， OpenDSS simulation software is used to analyze the influence after distributed generation(DG) access to distribution network， especially on the voltage, power loss and short-circuit current. Firstly， the principle and advantages of OpenDSS are explained from the aspects of model building, power flow calculation and short-circuit current. Then a practical case is established based on openDSS. Finally, the impacts of the capacity and location of DG are researched from the aspect of voltage, power loss and short-circuit current.